Rotary light switches for motor vehicles usually have the switch positions “off”, “parking light” and “traffic light”, between which a switching over is carried out by rotating the actuating member, and additional switch positions for “fog light” or “front fog light” and “rear fog light”, between which a switching over is carried out by axial movement of the actuating member. As the fog light is only permissible in combination with traffic light or at least parking light, measures are provided, by which particular combinations of rotary position/axial position of the actuating member are prevented. From the DE 38 34 390 C1 a rotary light switch is known, the actuating member of which has two control pins which are urged radially outwards by spring force. The outer ends of these pins are rounded in a spherical shape and run in a guide channel arranged on the inner face on the housing. The guide channel is provided with profile tracks which on the one hand form various detent zones to define the switch positions, and on the other hand have axially rising zones which force upon the actuating member an axial movement component on rotation over particular peripheral areas of the profile tracks. The guide channel has a complex geometry and is therefore difficult to produce. Since the control pins are pressed radially outwards against the profile tracks, movement of the actuating member is opposed by considerable friction, so that relatively high actuating forces are necessary.